Systems and methods for preparing tissue flaps

ABSTRACT

A system and method for holding a cutting tool at a predetermined distance from a defined cutting surface to prepare a tissue flap of substantially uniform thickness for optimal viability. A tissue holder plate having a vacuum chamber is provided to stabilize the tissue mass, and a cutting tool holder and guide plate restrict the movement of the cutting tool with respect to the tissue holder plate.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application represents the national stage entry of PCTInternational Application No. PCT/US2014/056889 filed Sep. 23, 2014,which claims priority to U.S. provisional patent application Ser. No.61/881,482, filed Sep. 24, 2013, of which are incorporated by referenceherein for all purposes.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH

N/A

BACKGROUND OF THE INVENTION

The present invention relates to systems and methods for preparing atissue flap from a tissue mass. More particularly, the invention relatesto a system for preparing the tissue flap using a tissue holder plate tostabilize the tissue mass and a guide plate for translating a cuttingtool in a predefined plane.

Tissue flaps are used and produced in many types of surgical procedures,particularly reconstructive surgery in a variety of indications tocorrect a multitude of tissue defects. For example, flaps may be used tocover (or can be created by incision in) a variety of wounds orresurface scars in the head, neck, extremities, and trunk or they may beemployed to cover exposed tendons, bones, or major blood vessels. Tissueflaps may be used about the face where color match and contour areimportant or they may be used to close wounds having a poor blood supplyas where wound circulation would not support a skin graft. A tissue flaptraditionally refers to skin and subcutaneous tissue (or muscle, bone,or other tissue) along with the entire vascular plexuses, therebybringing a large supply of tissue and an intact blood supply to the siteof injury. Modern surgical techniques have expanded the traditionaldefinition of a tissue flap to encompass free, microvascular flaps thatmay be anastomosed to an existing blood supply at or near the site ofinjury.

Tissue flaps are also produced during surgery. For example, tissue flapsare produced during breast reconstruction surgery wherein skin, fat, andthe rectus muscle from the abdomen are removed and re-located to thechest to make the new breast. Similarly, tissue flaps can be producedtemporarily during surgical procedures wherein surgical incisions aremade in a patient.

Preparation of tissue flaps for the above mentioned surgeries requireseparation of tissue layers often across not well-defined anatomicalplanes using a cutting tool, such as a scalpel or an electrosurgicaltool. Particularly when thin tissue flaps need to be developed, freehandsurgical techniques commonly result in an inconsistent tissue flapthickness, leading to localized damage of blood supply and relatedhealing complications. One non-limiting example of tissue flappreparation is the separation of skin and thin subcutaneous tissue frombreast tissue during mastectomy, where the goal is to preserve viableskin for proper healing and reconstruction. When performed inaccurately,the resulting and often extensive skin necrosis results in prolongedhealing and less effective reconstruction, often necessitatingadditional operations, and ultimately increasing the cost of care.

Therefore, there is a need for systems and methods to improve thecreation and use of tissue flaps, for example, to improve theconsistency of tissue flap creation.

SUMMARY OF THE INVENTION

The present invention overcomes the aforementioned drawbacks byproviding a system and method to move a cutting tool within the boundsof a predetermined tissue plane so that the prepared tissue flap is ofsubstantially uniform thickness for optimal viability. In particular,the present invention provides a tissue holder to stabilize, forexample, the outer surface of the skin, and a tool holder and guide thatrestricts the movement of the cutting instrument with respect to thetissue holder.

In accordance with one aspect of the invention, a surgical device forpreparing a tissue flap from a tissue mass is disclosed. The surgicaldevice may include a guide plate having a planar slot or a peripheralridge that surrounds the guide plate. The surgical device may furtherinclude a tissue holder plate defining a vacuum chamber configured tosecurely hold the tissue mass a predetermined distance from andorientation to the guide plate. A support handle may be coupled betweenthe guide plate and the tissue holder plate. Additionally, a tool holdermay be configured to receive a cutting tool for cutting the tissue flapfrom the tissue mass. The tool holder includes a tool holder platecoupled to a base. The tool holder plate may be dimensioned to engagethe guide plate and translate or rotate within the peripheral ridge orslot to restrict movement of the cutting tool to a predefined planerelative to the tissue mass and the tissue holder plate. The tool holderfurther includes a guide arm coupled to the base of the tool holder at apredetermined angle relative to the tool holder plate and configured toengage the cutting tool. The movement of the tool holder plate withinthe peripheral ridge or slot of the guide plate enables the cutting toolto cut the tissue mass in the predefined plane at the predeterminedangle, thereby preparing a tissue flap with a substantially uniformpredetermined thickness from the tissue mass.

In accordance with another aspect of the invention a method forpreparing a tissue flap from a tissue mass is disclosed. The methodincludes the steps of providing a guide plate including a peripheralridge or a slot and attaching a vacuum chamber to a tissue holder plate.The tissue mass may be suctioned to the tissue holder plate apredetermined distance from the guide plate. A tool holder plate may betranslated and rotated within the peripheral ridge or slot of the guideplate in a predefined plane and the tool holder plate may include acutting tool attached thereto at a predetermined angle. The tissue massmay then be cut in the predefined plane at the predetermined angle toprepare the tissue flap with a substantially uniform thickness from thetissue mass.

In accordance with another aspect of the invention a surgical device forpreparing a tissue flap from a tissue mass is disclosed. The surgicaldevice includes an electro-mechanical actuator in communication with acomputer controller having stored thereon a control algorithm. Thesurgical device further includes a tissue holder plate configured tosecurely hold the tissue mass a predetermined distance from andorientation to the electro-mechanical actuator. A support member iscoupled between the electro-mechanical actuator and the tissue holderplate, and a tool holder is coupled to the electro-mechanical actuatorand configured to receive a cutting tool for cutting the tissue flapfrom the tissue mass. The control algorithm is configured to restrictmovement of the cutting tool to a predefined range of motion relative tothe tissue mass and the electro-mechanical actuator in order to enablethe cutting tool to cut the tissue mass in the predefined range ofmotion, thereby preparing a tissue flap with a substantially uniformpredetermined thickness from the tissue mass.

The foregoing and other aspects and advantages of the invention willappear from the following description. In the description, reference ismade to the accompanying drawings which form a part hereof, and in whichthere is shown by way of illustration a preferred embodiment of theinvention. Such embodiment does not necessarily represent the full scopeof the invention, however, and reference is made therefore to the claimsand herein for interpreting the scope of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view of an example surgical device including a toolholder holding a cutting tool, a guide plate, and a tissue holder plateaccording to one embodiment of the present invention.

FIG. 2 is a perspective view of the example surgical device of FIG. 1including a vacuum chamber and a vacuum hose attachment for providingsuction to a tissue mass according to one embodiment of the presentinvention.

FIG. 3 is a perspective view of the tissue holder plate includingsuction cups for providing suction to a tissue mass according to oneembodiment of the present invention.

FIG. 4 is a perspective view of the tissue holder plate including one ormore sub-plates according to one embodiment of the invention.

FIG. 5 is a perspective view of the tool holder of FIG. 1 including abase, a tool holder plate, and a guide arm according to one embodimentof the present invention.

FIGS. 6A-6D are perspective views of the tool holder of FIG. 1 beingtranslated within a predefined plane of the guide plate according to oneembodiment of the present invention.

FIG. 7 is a flow chart setting forth the steps of processes for creatinga tissue flap from a tissue mass in accordance with the presentinvention.

FIG. 8 is a plan view of another example surgical device including atool holder holding a cutting tool, a guide plate, and a tissue holderplate according to one embodiment of the present invention.

FIG. 9 is a perspective view of the example surgical device of FIG. 8including a vacuum chamber, a vacuum hose attachment for providingsuction to a tissue mass, and a support arm according to one embodimentof the present invention.

FIG. 10 is a perspective view of the tool holder of FIG. 8 including abase, a tool holder plate, and a guide arm according to one embodimentof the present invention.

FIGS. 11A-11D are perspective views of the tool holder of FIG. 8 beingtranslated within a predefined plane of the guide plate according to oneembodiment of the present invention.

FIG. 12 is a perspective view of the example surgical device of FIG. 8according to one embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Referring particularly now to FIGS. 1 and 2, a surgical device 10 isshown that is configured to prepare a tissue flap (not shown), having asubstantially uniform thickness 12, from a tissue mass (not shown) usinga cutting tool 14 during surgery. The surgery may be, for example, amastectomy, a reconstructive surgery, a facelift, a thin flap evaluationin mastectomy, a general flap elevation, or any other surgical procedurewhere a tissue flap of generally uniform thickness may be advantageous.The surgical device 10 may be disposable or non-disposable, and mayinclude, for example, a tissue holder plate 16 and a guide plate 18spaced a predetermined distance 20 apart. The predetermined distance 20may be determined by the length of a support member 22 having a proximalend 24 and a distal end 26. A support handle 28 may extend proximate tothe proximal end 24 and extend toward the distal end 26 of the supportmember 22 and may be coupled thereto.

The tissue holder plate 16 may be coupled to the distal end 26 of thesupport member 22 and include a perforated plate 30 and a vacuum chamber32 for suctioning the tissue mass. The vacuum chamber 32 may extend froma vacuum hose attachment 34 through the support member 22, and into thetissue holder plate 16 and through the perforated plate 30. The guideplate 18 may be coupled to the proximal end 24 of the support member 22and include a peripheral ridge 36 surrounding the edges, therebycreating a predefine plane 38.

The predefined plane 38 of the guide plate 18 may be configured, forexample, to receive a tool holder 40 capable of translating and rotatingwithin the predefined plane 38. The tool holder 40 may include a base 42configured to receive the cutting tool 14. A guide arm 44 may be coupledto the base 42 and configured to restrict lateral movement of thecutting tool 14. Attached to a top portion 48 of the base 42 may be atool holder plate 46. The tool holder plate 46 may be configured, forexample to translate or rotate within the predefined plane 38 defined bythe peripheral ridge 36 of the guide plate 18 so that a tip 50 of thecutting tool 14 moves in a defined planar region to cut the tissue flapwith the substantially uniform thickness 12.

Referring particularly to FIG. 2, the surgical device 10, in absence ofthe tool holder 40, which will be described in further detail below, isshown. The tissue mass may be held, for example, by the perforated plate30 attached to the vacuum chamber 32 so that the tissue mass is held atthe predetermined distance 20 and in geometric relationship to the guideplate 18. Suction may be provided through the vacuum hose attachment 34,and the amount of suction may be controlled via a valve system 76 toadjust the amount of suction, and to release the suction, when thecutting operation is complete. The perforated plate 30 may includecircular perforations 52 of various diameters and positioned in variousdistributions depending on the particular surgical procedure, theanatomy of the patient or the needs of the tissue mass fixation. In analternative embodiment, the perforations 52 may be of any suitablegeometric shape or size required for suction of the tissue mass, or theperforations 52 may be replaced, or used in conjunction, with anysuitable interface to enhance the suction capability.

For example, in the embodiment shown in FIG. 3, the tissue holder plate16 includes a plurality of suction cups 53 extending from each one ofthe perforations 52. Thus, each suction cup 53 includes an opening tocreate a passageway from the suction cup 53 to the vacuum chamber 32 tohold the tissue mass in geometric relationship to the guide plate 18.The suction cups 53 may be constructed from a soft, rubber material,however any suitable material may be used. Suction may be providedthrough the vacuum hose attachment 34 such that each suction cup 53coupled to the perforations 52 could minimize loss of negative pressuredue to an imperfect seal between the tissue holder plate 16 material andthe surface of the tissue mass.

In one non-limiting example, the suction provided through the vacuumhose attachment 34 to hold the tissue mass in place may be used inconjunction with, or replaced by, a surgical glue or gel to secure thetissue mass to the tissue holder plate 16. The surgical glue and/or gelmay be advantageous to secure the tissue mass, as during some surgicalprocedures, the cutting tool 14 (e.g., a bovie) can reach hightemperatures and cause damage to the tissue. In one non-limitingexample, the glue and/or gel may be provided in the form of a liquidthat is directly applied to the tissue holder plate 16 and/or thepatient's skin. Alternatively, the glue may be provided in the form of adouble-sided adhesive patch (not shown) that may be applied to thetissue holder plate 16. The properties of the double-sided adhesivepatch could securely hold the tissue mass during the cutting operations,but may be peeled away easily from the tissue mass and the tissue holderplate 16 when cutting is complete. In one embodiment, the double-sidedadhesive patch may be disposable so that a fresh patch can be used foreach cutting procedure or the patch may be used for two or more tissueareas prior to being replaced. In a further embodiment, the adhesivepatch may also include areas that operate like suction cups, similar tothe suction cups 53 previously described, that interface with the vacuumchamber 32 so that the suction and adhesive are complementary. Further,the double-sided adhesive patches may be provided in sterile packages insuitable quantities for the target procedures and may be sized to matchthe geometry of the tissue holder plate 16.

In addition, a surgical gel or other compound may help maintain thermalstability of the tissue. Depending on the procedure, it may beadvantageous for the glue to contain pharmaceutical compounds or otheringredients that help promote tissue viability. Alternatively, hook-likedevices (not shown) may be coupled to the tissue holder plate 16 tograsp the tissue securely. The hook-like devices could be used with thesurgical glue or gel and/or with the vacuum hose attachment 34, or alltogether.

The dimensions of the perforated plate 30, as well as the tissue holderplate 16, the guide plate 18, the support member 22, and the supporthandle 28, for example, may also be varied according to the needs of theparticular surgical procedures and/or the anatomy of the patient. Theanatomy of the patient, for example, may not be flat, but rather curvedor shaped based on the application. In one non-limiting example, theperforated plate 30, the tissue holder plate 16 and the guide plate 18may be rectangular in shape and have dimensions of, for example, 2inches by 3 inches. The support handle 28 may be approximately 6 inchesin length and the support member 22 may be approximately 10 inches inlength for preparation of tissue flaps during mastectomy. Alternatively,the perforated plate 30, the tissue holder plate 16 and the guide plate18 may have proportionately smaller dimensions, and the support member22 and the support handle 28 may be proportionately shorter in lengthfor procedures, such as reconstructive surgery of facial features. Thelength of the support member 22, therefore, may determine thepredetermined distance 20 between the guide plate 18 and the tissueholder plate 16.

The perforated plate 30, the tissue holder plate 16 and the guide plate18 are not limited to the rectangular dimensions provided above. In analternative embodiment, the perforated plate 30, the tissue holder plate16 and the guide plate 18 may be of any suitable geometric shape, forexample square, circular, ring shaped, curved in three-dimensions or anycombination thereof. Further, the perforated plate 30, the tissue holderplate 16 and the guide plate 18 can be constructed of any suitablemedical grade material such as stainless steel, plastic, titanium orrubber polymers. FIG. 2 shows planar surfaces 54 for the perforatedplate 30, the tissue holder plate 16 and the guide plate 18. However, inan alternative embodiment the perforated plate 30, the tissue holderplate 16 and the guide plate 18 may have non-linear surfaces (not shown)to better conform to anatomy and to customize the resulting tissue flapshape to meet clinical targets, for example. In a particularnon-limiting example, the surfaces of the perforated plate 30, thetissue holder plate 16, and the guide plate 18 may be parallel to thesupport member 22 along any cross section along the axis parallel to thesupport member 22, but have a semi-circular cross section along the axisperpendicular to support member 22.

In another example, it may be advantageous for the shape of the cuttingplane 54 to closely conform to the anatomical contours of a particularpatient's anatomy. There exist in the art techniques to determine thisanatomical surface information, for example through the use of medicalimaging techniques such as CT or MR scanning and subsequentpost-processing. Well known techniques exist for creating physicalobjects based on this geometry, for example through computer controlledmilling or 3D printing. Thus, the exact shape and size of the guideplates 16, 18 may be determined based on patient-specific measurementinformation.

In another example, it may be advantageous to select the shape of theguide plates 16, 18 based on the particular surgical procedure to beperformed. For example, a surgeon may determine that a nipple-sparingmastectomy procedure is appropriate for the patient and, through the useof medical imaging and custom manufacturing, a patient-specific andprocedure-specific surface geometry may be defined. Suchpatient-specific and/or procedure-specific custom instrumentation mayinclude, for example, a tissue holder 16 that encompasses the entiretarget anatomical structure, such as a tissue holder that holds theentire breast. Alternatively, the tissue holder 16 may include multiplesections that are used sequentially or in parallel to carry out therequired steps of the surgical procedure.

In yet another non-limiting example, the perforated plate 30 and thetissue holder plate 16 may be composed of two or more sub-plates 31, 33,as shown in FIG. 4. Each sub-plate 31, 33 may be a perforated plate,similar to the perforated plate 30, and include independent vacuumchambers 32 for suctioning the tissue mass. The sub-plates may include ahinge 35, for example, that allows the sub-plates to fold back from thepatient when not needed. In addition, when folded into place, thesub-plates 31, 33 may be configured to lock, such that the combinationof the sub-plates 31, 33 are rigid and form a solid base for holding thetissue and supporting exact tissue dissection. The sub-plates 31, 33 mayfurther include one or more support posts 37 that extend between theperforations 52 in the vacuum chamber 32.

Additionally, or alternatively, the perforated plate 30 and the tissueholder plate 16 may be composed of multiple strips of sub-plates, suchthat an exact length of the tissue holder plate 16 and the perforatedplate 30 could be controlled. Thus, a range of standard tissue holderplate 16 sizes may be used during different parts of a surgicalprocedure depending on the portion of the tissue, such as breast tissue,being prepared.

Similarly, the support handle 28 may be of any suitable geometric shape.For example, the support handle 28 is shown in FIG. 2 with a cylindricalhandle so that the surgeon may easily manipulate the surgical device 10and tissue mass during the procedure. The precise shape of the supporthandle 28 may be readily adapted for better ergonomics, for example,depending on the overall size of the tissue mass to be manipulated.Further, the support handle 28 may be constructed of any suitablemedical grade material such as plastic, titanium or rubber polymers.

Turning now to FIG. 5, the tool holder 40 is shown. As previouslydescribed, the tool holder plate 46 of the tool holder 40 is configuredto translate and rotate within the predefined plane 38 defined by theperipheral ridge 36 of the guide plate 18 so that the tip 50 of thecutting tool 14, as shown in FIG. 1, moves in a defined planar region tocut the tissue flap with the substantially uniform thickness 12.Alternatively, the tool holder plate 46, the tissue holder plate 16, andthe guide plate 18 may be in the shape of a half cylinder, for example,so that the tissue holder plate 16 better fits the anatomical form ofthe target tissue. As the tool holder 40 translates within thepredefined half cylinder surface (not shown), the tissue flap being cutfollows the three-dimensional body contour while preserving the uniformtissue thickness. The tool holder plate 46 may be any suitable size(e.g., 1 inch by 1 inch, or 2 inches by 1 inch) and geometric shape(e.g., square, rectangular or circular) to allow movement within thearea defined by the peripheral ridge 36 around the guide plate 18.Further, the tool holder 40 can be constructed of any suitable medicalgrade material such as plastic, titanium or rubber polymers. The sizeand shape of the tool holder 40 may be adjusted according to theparticular surgical procedure, the anatomy of the patient or the needsof the tissue mass fixation.

The base 42 of the tool holder 40 may include an aperture 56, forexample a circular aperture, and a cord slot 58 configured to receive abase 60 of the cutting tool 14 and a cord 62 of the cutting tool 14, asshown in FIG. 1, respectively. The guide arm 44 may be fixed to the base42 or attached to the base 42 with a sliding linkage 80, as shown inFIG. 5, that is configured to slide vertically, and therefore thecutting tool 14 is slid vertically as well, to select the substantiallyuniform thickness 12 of the tissue flap. Alternatively, the tool holder40 may be custom fabricated based on the cutting tool 14. The guide arm44 may be, for example, a cylindrical cut out 74 as shown in FIG. 5. Theshape of the aperture 56, the cord slot 58, and the guide arm 44 mayvary depending on the type of cutting tool 14 being used (i.e., ascalpel, an electrosurgical tool, a pencil, scissors, or a Bovie knife).Alternatively, the guide arm may be a clamp or other mechanicalattachment. The guide arm 44 may be coupled to the base 42 of the toolholder 40 to form a predetermined angle 64 at which the cutting tool 14is held, as shown in FIG. 1, with respect to the tissue mass. Thepredetermined angle 64 can be adjusted, for example, by the geometricdesign of the guide arm 44 and how the guide arm 44 is attached to thebase 42.

In one example, the predetermined angle 64 may be adjustable at the timeof the procedure by including a hinge-like mechanism (not shown) thatallows the angle 64 to be set and locked in place as needed. Thehinge-like mechanism may be configured to be releasable during theprocedure to facilitate a more free-hand movement of the tool holder 40,while allowing the tool holder 40 to be re-locked to the originalpredefine angle 64, for example by including markings on the hinge sothat the correct angle can be easily set.

In some embodiments, the cutting tool 14, similar to the tool holder 40,may also be custom fabricated. For example, the cutting tool 14 may be acustom tool with multiple functions, such as a forward facing scalpelblade that has integrated cautery functionality. Thus, when a bleedoccurs, the cautery could be applied without removing the cutting tool14. Alternatively, suction may be integrated into the cutting tool 14,such that the tissue mass could be cut, and then blood may be suctionedaway prior to applying cautery, again without removing the cutting tool14. In yet another embodiment, a wedge (not shown) may be used hold thetissue mass, such as breast gland tissue, away from the cutting surface.The wedge may provide some tension at the site of the dissection, andcould use one or more of the tissue fixation techniques (e.g., vacuum,hooks, surgical glue, etc.), as previously described, to firmly hold thetissue mass. In addition, the cutting tool 14 may be custom fabricatedto include a video camera or endoscope, for example, to providevisualization when operating deep within the tissue mass, for examplenear the chest wall in mastectomy of a large breast.

Turning now to FIGS. 6A-6D illustrations of the relative motion of thetool holder 40, and more specifically, the tool holder plate 46, in thepredefined plane 38 with respect to the guide plate 18 and the tissueholder plate 16 is shown. As the tool holder 40 is moved from a firstposition 66, as shown in FIG. 6A, in the predefined plane 38, to asecond position 68, as shown in FIG. 6B, for example, the tool holderplate 46 slides relative to the guide plate 18 while maintaining thesubstantially uniform thickness 12 of the tissue flap. The tool holder40 may be moved from the second position 68, as shown in FIG. 6B to athird position 70, as shown in FIG. 6C, for example while stillmaintaining the substantially uniform thickness 12 of the tissue flapbeing cut by the cutting tool 14. As the tool holder 40 is moved amongthe exemplary positions, the tool holder 40 may also be rotated, asshown in FIG. 6D, within the predefined plane 38 while maintaining thesubstantially uniform thickness 12 of the tissue flap. Also shown inFIG. 6D is the tissue holder plate 16 having a non-rectangular shapewhich may be advantageous for certain procedures.

In addition, as the tool holder 40 is moved among the exemplarypositions, as shown in FIGS. 6A-6D, within the predefined plane 38, acutting plane 72 is defined about the tissue mass being held in place bythe tissue holder plate 16. The cutting plane 72 is therefore defined bythe relative dimensions of the tool holder plate 46 and the guide plate18. It will be appreciated that the relative size of the cutting plane72 can be varied according to the selected dimensions of guide plate 18or the tool holder plate 46, or a combination thereof.

In an alternative embodiment, the guide plate 18 and the tool holderplate 46 may be attached such that they remain in approximation whilethe tool holder 40 is moved among the first position 66, the secondposition 68, and the third position 70, as shown in FIGS. 6A, 6B and 6C,respectively. For example, a linkage 78, as shown in FIG. 1, could beused to hold the guide plate 18 and the tool holder plate 46 togetherwhile allowing freedom of movement within the two-dimensional predefinedplane 38. Note, however, the tool holder 40 is not restricted to thepositions shown in FIGS. 6A-6C, but may move to any position within thepredefined plane 38. As a non-limiting example, the linkage 78 betweenthe tool holder plate 46 and the guide plate 18 may be accomplished byembedding a magnet 82, as shown in FIG. 5, of suitable strength in thetool holder plate 46 and forming the guide plate 18 out of steel or anyother suitable material attracted to the magnet. Through selection ofappropriate magnetic strengths and controlling for the frictionalproperties of the materials, the tool holder plate 46 and the guideplate 18 can be made to slide easily through all positions within thepredefined plane 38, while remaining stably attached to ensure that thesubstantially uniform thickness 12 is maintained during the cutting andtissue manipulation processes. As another non-limiting example, thelinkage 78 between tool holder plate 46 and guide plate 18 may beaccomplished through the use of articulating arms constructed so as toensure that the guide plate 18 remains in approximation with the tissueholder plate 16 while allowing free motion within the predefined plane38.

Referring now to FIG. 7, a flow chart setting forth exemplary steps 100for preparing the tissue flap from the tissue mass is provided. To startthe process, the guide plate 18 is provided at process block 102. Theguide plate 18 includes a peripheral ridge or a planar slot thatdetermines the predefined plane 38 wherein the tissue mass may be cut.At process block 104, external suction may be provided through thevacuum hose attachment 34, and the amount of suction may be controlledvia the valve system 76 to adjust the amount of suction in the vacuumchamber 32. The vacuum chamber 32 may provide suction to suction thetissue mass to the tissue holder plate 16 at process block 106. Aspreviously described, the tissue holder plate 16 may include aperforated plate 30 for suctioning the tissue mass to the tissue holderplate 16. At process block 108, the tool holder 40 is translated and/orrotated within the predefined plane 38. The tissue mass is cut in thecutting plane 72 that is defined by the predefined plane 38, aspreviously described, at process block 110. The tissue flap is preparedwith the substantially uniform thickness 12 at process block 112. Oncethe tissue flap is completely cut from the tissue mass at process block112, the suction provided by the vacuum chamber 32 is released to endthe procedure at process block 114.

Referring particularly now to FIGS. 8 and 9, another exemplary surgicaldevice 200, similar to the previously described surgical device 10, isshown. The surgical device 200 is configured to prepare a tissue flap(not shown), having a substantially uniform thickness 212, from a tissuemass (not shown) using a cutting tool 214 during surgery. The surgerymay be, for example, a mastectomy, a reconstructive surgery, a facelift,a thin flap evaluation in mastectomy, a general flap elevation, or anyother surgical procedure where a tissue flap of generally uniformthickness may be advantageous. The surgical device 200 may be disposableor non-disposable, and may include, for example, a tissue holder plate216 and a guide plate 218 spaced a predetermined distance 220 apart. Thepredetermined distance 220 may be determined by the length of a supportmember 222 having a proximal end 224 and a distal end 226. The supportmember 222 may also be used as a support handle for a user to grasp, forexample.

The tissue holder plate 216 may be coupled to the distal end 226 of thesupport member 222 and include a perforated plate 230 and a vacuumchamber 232 for suctioning the tissue mass. The vacuum chamber 232 mayextend from a vacuum hose attachment 234, into the tissue holder plate216 and through the perforated plate 230. The guide plate 218 may becoupled to the proximal end 224 of the support member 222 and include aslot 236 on a bottom surface of the guide plate 218, thereby creating apredefined plane 238. In an alternative embodiment, the slot 236 may bepositioned on a top surface of the guide plate 218.

The predefined plane 238 of the guide plate 218 may be configured, forexample, to receive a tool holder 240 capable of translating androtating within the predefined plane 238. The tool holder 420 mayinclude a base 242 configured to receive the cutting tool 214. A guidearm 244, having an aperture 245 for receiving the cutting tool 214, maybe coupled to the base 242 and configured to restrict lateral movementof the cutting tool 214. Attached to a top portion 248 of the base 242may be a tool holder plate 246, which may be in the form of a tongue,for example. The tool holder tongue 246 may be received in the slot 236of the guide plate 218 and configured, for example to translate androtate within the predefined plane 238 defined by the slot 236 of theguide plate 218 so that a tip 250 of the cutting tool 214 moves in adefined planar region to cut the tissue flap with the substantiallyuniform thickness 212. In some embodiments, the tip 250 of the cuttingtool 214 may be curved, as shown in FIG. 8, such that the cutting planeis substantially parallel to the tissue holder plane, which is definedby the tissue holder plate 216.

Referring particularly to FIG. 9, the surgical device 200, in absence ofthe tool holder 240, which will be described in further detail below, isshown. The tissue mass may be held, for example, by the perforated plate230 attached to the vacuum chamber 232 so that the tissue mass is heldat the predetermined distance 220 and in geometric relationship to theguide plate 218. A support arm 247 may be provided in order to attachthe surgical device 200 to a surface 249, such as an operating roomtable. The support arm 247, at one end, may be coupled to the tissueholder plate 216. A securing mechanism 251, such as a clamp, may becoupled to an opposing end of the support arm 247 to secure the surgicaldevice 200 to the operating room table 249. Thus, the clinician can havethe tissue mass securely held in place along with the surgical device200 and allowing one hand to be used to move the cutting tool 214 andthe other hand to be used to hold the tissue mass, such as breast glandtissue.

In some embodiments, the support arm 247 includes a plurality of looseparts 253 that are hingeable with respect to one another. The pluralityof loose parts 253 maybe connected, for example, by a flexible tensionrod (not shown) extending through a central bore of the support arm 247.Thus, the support arm 247 can be adjusted and locked in any desiredposition with respect to the tissue mass. It is also possible to placethe tissue holder plate 216 in a precise location relative to the tissuemass. Once the support arm 247 and surgical device 200 are adjusted tothe desired position, the position can be fixed by locking the flexibletension rod. In one non-limiting example, the support arm 247 can bedetachable from the tissue holder plate 216 of the surgical device 200,or alternatively, the support arm 247 may be permanently attached to thesurgical device 200.

Once the support arm 247 and surgical device 200 are in the desiredposition, suction may be provided through the vacuum hose attachment234, and the amount of suction may be controlled via a valve system 276to adjust the amount of suction, and to release the suction, when thecutting operation is complete. The perforated plate 230 may includecircular perforations 252 of various diameters and positioned in variousdistributions depending on the particular surgical procedure, theanatomy of the patient or the needs of the tissue mass fixation. In analternative embodiment, the perforations 252 may be of any suitablegeometric shape or size required for suction of the tissue mass, or theperforations 252 may be replaced, or used in conjunction, with anysuitable interface to enhance the suction capability.

For example, as previously described with respect to FIG. 3, the tissueholder plate 216 may include the plurality of suction cups 53 extendingfrom each one of the perforations 52. Thus, each suction cup 53 includesan opening to create a passageway from the suction cup 53 to the vacuumchamber 32 to hold the tissue mass in geometric relationship to theguide plate 18. The suction cups 53 may be constructed from a soft,rubber material, however any suitable material may be used. Suction maybe provided through the vacuum hose attachment 34 such that each suctioncup 53 coupled to the perforations 52 could minimize loss of negativepressure due to an imperfect seal between the tissue holder plate 216material and the surface of the tissue mass.

In one non-limiting example, the suction provided through the vacuumhose attachment 234 to hold the tissue mass in place may be used inconjunction with, or replaced by, a surgical glue or gel to secure thetissue mass to the tissue holder plate 216. The surgical glue and/or gelmay be advantageous to secure the tissue mass, as during some surgicalprocedures, the cutting tool 214 (e.g., a bovie) can reach hightemperatures and cause damage to the tissue. In one non-limitingexample, the glue and/or gel may be provided in the form of a liquidthat is directly applied to the tissue holder plate 216 and/or thepatient's skin. Alternatively, the glue may be provided in the form of adouble-sided adhesive patch (not shown) that may be applied to thetissue holder plate 216. The properties of the double-sided adhesivepatch could securely hold the tissue mass during the cutting operations,but may be peeled away easily from the tissue mass and the tissue holderplate 216 when cutting is complete. In one embodiment, the double-sidedadhesive patch may be disposable so that a fresh patch can be used foreach cutting procedure or the patch may be used for two or more tissueareas prior to being replaced. In a further embodiment, the adhesivepatch may also include areas that operate like suction cups, similar tothe suction cups 53 previously described, that interface with the vacuumchamber 232 so that the suction and adhesive are complementary. Further,the double-sided adhesive patches may be provided in sterile packages insuitable quantities for the target procedures and may be sized to matchthe geometry of the tissue holder plate 216.

In addition, a surgical gel or other compound may help maintain thermalstability of the tissue. Depending on the procedure, it may beadvantageous for the glue to contain pharmaceutical compounds or otheringredients that help promote tissue viability. Alternatively, hook-likedevices (not shown) may be coupled to the tissue holder plate 216 tograsp the tissue securely. The hook-like devices could be used with thesurgical glue or gel and/or with the vacuum hose attachment 234, or alltogether.

The dimensions of the perforated plate 230, as well as the tissue holderplate 216, the guide plate 218, and the support member 222, for example,may also be varied according to the needs of the particular surgicalprocedures and/or the anatomy of the patient. The anatomy of thepatient, for example, may not be flat, but rather curved or shaped basedon the application. In one non-limiting example, the perforated plate230, the tissue holder plate 216 and the guide plate 218 may berectangular in shape and have dimensions of, for example, 2 inches by 3inches. The support member 222 may be approximately 10 inches in lengthfor preparation of tissue flaps during mastectomy. Alternatively, theperforated plate 230, the tissue holder plate 216 and the guide plate218 may have proportionately smaller dimensions, and the support member222 may be proportionately shorter in length for procedures, such asreconstructive surgery of facial features. The length of the supportmember 222, therefore, may determine the predetermined distance 220between the guide plate 218 and the tissue holder plate 216.

As previously described, the perforated plate 230, the tissue holderplate 216 and the guide plate 218 are not limited to the rectangulardimensions provided above. In an alternative embodiment, the perforatedplate 230, the tissue holder plate 216 and the guide plate 218 may be ofany suitable geometric shape, for example square, circular, curved inthree-dimensions or any combination thereof. Further, the perforatedplate 230, the tissue holder plate 216 and the guide plate 218 can beconstructed of any suitable medical grade material such as stainlesssteel, plastic, titanium or rubber polymers. FIG. 9 shows planarsurfaces 254 for the perforated plate 230, the tissue holder plate 216and the guide plate 218. However, in an alternative embodiment theperforated plate 230, the tissue holder plate 216 and the guide plate218 may have non-linear surfaces (not shown) to better conform toanatomy and to customize the resulting tissue flap shape to meetclinical targets, for example. In a particular non-limiting example, thesurfaces of the perforated plate 230, the tissue holder plate 216, andthe guide plate 218 may be parallel to the support member 222 along anycross section along the axis parallel to the support member 222, buthave a semi-circular cross section along the axis perpendicular tosupport member 222.

In yet another non-limiting example, the perforated plate 230 and thetissue holder plate 216 may be composed of two or more sub-plates, suchas the sub-plates shown in FIG. 4. Each sub-plate 31, 33 may be aperforated plate, similar to the perforated plate 230, and includeindependent vacuum chambers 32 for suctioning the tissue mass. Thesub-plates may include a hinge 35, for example, that allows thesub-plates to fold back from the patient when not needed. In addition,when folded into place, the sub-plates 31, 33 may be configured to lock,such that the combination of the sub-plates 31, 33 are rigid and form asolid base for holding the tissue and supporting exact tissuedissection. The sub-plates 31, 33 may further include one or moresupport posts 37 that extend between the perforations 52 in the vacuumchamber 32.

Turning now to FIG. 10, the tool holder 240 is shown. As previouslydescribed, the tool holder tongue 246 of the tool holder 240 isconfigured to translate and rotate within the predefined plane 238defined by the slot 236 of the guide plate 218 so that the tip 250 ofthe cutting tool 214, as shown in FIG. 8, moves in a defined planarregion to cut the tissue flap with the substantially uniform thickness212. The tool holder tongue 246 may be inserted into the slot 236 of theguide plate 218 from a direction away from a cutting plane 272 such thatthe tool holder 240 and cutting tool 214 may be introduced to thedesired position relative to the tissue mass.

Alternatively, the tool holder plate 246, the tissue holder plate 216,and the guide plate 218 may be in the shape of a half cylinder, forexample, so that as the tool holder 240 translates within the predefinedhalf-cylinder 238, the tissue flap being cut more closely conforms tothe three-dimensional shape of the tissue. The tool holder plate 246 maybe any suitable size (e.g., 1 inch by 1 inch, or 2 inches by 1 inch) andgeometric shape (e.g., square, rectangular or circular) to allowmovement within the area defined by the slot 236 of the guide plate 218.Further, the tool holder 240 can be constructed of any suitable medicalgrade material such as plastic, titanium or rubber polymers. The sizeand shape of the tool holder 240 may be adjusted according to theparticular surgical procedure, the anatomy of the patient or the needsof the tissue mass fixation.

The guide arm 244 of the tool holder 240 may include the aperture 245,for example a circular aperture, and a cord slot 258 configured toreceive a base 260 of the cutting tool 214 and a cord 262 of the cuttingtool 214, as shown in FIG. 8, respectively. As previously described, thetool holder 240 may be custom fabricated based on the cutting tool 214.The shape of the aperture 245, the cord slot 258, and the guide arm 244may vary depending on the type of cutting tool 214 being used (i.e., ascalpel, an electrosurgical tool, a pencil, or a Bovie knife).Alternatively, the guide arm 244 may be a clamp or other mechanicalattachment. The guide arm 244 may be integrally coupled to the base 242,for example, of the tool holder 240 to form a predetermined angle 264 atwhich the cutting tool 214 is held, as shown in FIG. 8, with respect tothe tissue mass. The predetermined angle 264 can be adjusted, forexample, by the geometric design of the guide arm 244 and how the guidearm 244 is attached to the base 242.

Turning now to FIGS. 11A-11D illustrations of the relative motion of thetool holder 240, and more specifically, the tool holder plate 246, inthe predefined plane 238 with respect to the guide plate 218 and thetissue holder plate 216 is shown. As the tool holder 240 is moved from afirst position 266, as shown in FIG. 11A, in the predefined plane 238,to a second position 268, as shown in FIG. 11B, for example, the toolholder plate 246 slides relative to the slot 236 of the guide plate 218while maintaining the substantially uniform thickness 212 of the tissueflap. The tool holder 240 may be moved from the second position 268, asshown in FIG. 11B to a third position 270, as shown in FIG. 11C, forexample while still maintaining the substantially uniform thickness 212of the tissue flap being cut by the cutting tool 214. As the tool holder240 is moved among the exemplary positions, the tool holder 240 may alsobe rotated, as shown in FIG. 11D, within the predefined plate 238 whilemaintaining the substantially uniform thickness 212 of the tissue flap.Also shown in FIG. 11D is the tissue holder plate 216 having anon-rectangular shape which may be advantageous for certain procedures.

In addition, as the tool holder 240 is moved among the exemplarypositions, as shown in FIGS. 11A-11D, within the predefined plane 238, acutting plane 272 is defined about the tissue mass being held in placeby the tissue holder plate 216. The cutting plane 272 is thereforedefined by the relative dimensions of the tool holder plate 246 and theslot 236 of the guide plate 218. It will be appreciated that therelative size of the cutting plane 272 can be varied according to theselected dimensions of slot 236 of the guide plate 218 or the toolholder plate 246, or a combination thereof.

In an alternative embodiment, the guide plate 218 and the tool holderplate 246 may be attached such that they remain in approximation whilethe tool holder 240 is moved among the first position 266, the secondposition 268, and the third position 270, as shown in FIGS. 11A, 11B and11C, respectively. Note, however, the tool holder 240 is not restrictedto the positions shown in FIGS. 11A-11C, but may move to any positionwithin the predefined plane 238. Thus, the guide plate 218 remains inapproximation with the tissue holder plate 216 while allowing freemotion within the predefined plane 238.

Turning now to FIG. 12, another embodiment of a surgical device 300 isshown. The surgical device 300 may include one or more of the featuresas described with respect to the surgical devices 10 and 200. Thus,similar reference numerals are used to describe the components andfeatures of the surgical device 300 shown in FIG. 12 as were used todescribe the surgical devices 10 and 200. The surgical device 300 mayadditionally include a robot, for example, to maintain the predeterminedtissue thickness rather than relying on the mechanical constraint of thetongue and slot system.

As shown in FIG. 12, the movement of the cutting tool 314 relative tothe tissue holder plate 316 may be accomplished by electro-mechanical(i.e.; robotic) means. In the embodiment shown in FIG. 12, the tool 314is moved according to a multi-degree-of-freedom computer controlledactuator 301 that is in communication with a controller computer 303. Inone example, the surgical device 300 may have a six degree-of-freedomtracking of the tissue holder plate 316 and the tool 314 motion withrespect to a common coordinate frame of reference, using techniques suchas optical tracking, magnetic tracking, or through encoders at eachjoint 305 of the articulated electromechanical arm 301. The computercontroller 303 may have stored thereon a control algorithm to imposevirtual fixture constraints that prevent the tool 314 from movingoutside of a predefined range of motion. Additionally, or alternatively,the articulated electromechanical arm 301 may include force sensors (notshown), to allow an operator to freely move the arm 301 within theconstrained geometry while inhibiting motion outside of it. Thus, inthis embodiment, it is possible to create a tissue holder plate 316 withany patient-specific and/or procedure specific surface suitable for thesurgical procedure. Additionally, or alternatively, the tissue holderplate 316 may be mounted on a similar electro-mechanical arm (not shown)so that its motion can be coordinated with the tool 314 under thecontrol of the controlling computer 303. Motion of the tissue holderplate 316 would allow, as a non-limiting example, for the dissected skintissue to be pulled away from the underlying breast tissue duringmastectomy in order to better expose the cutting surface.

As described earlier, well known medical imaging technologies such as CTand MR scans can be used to make detailed maps of the patient anatomy,and in particular the scans can be used to identify critical structuresand to inform clinical decision making in order to optimize surgicalplans. An aspect of the current invention is the ability to incorporateinformation from these scan into the algorithm running on thecontrolling computer 303 such that the surgeon is informed during theprocedure based on information derived from the images. As anon-limiting example, MR or CT angiographic imaging could be used todetermine the location of blood vessels and the controlling computer 303could be programmed to activate an auditory and/or visual alert when thecutting tool is approaching a blood vessel.

In another embodiment of the present invention, active sensors may beincorporated into the tissue holder plate 316 or tool 314 to providereal-time monitoring of the procedure. As a non-limiting example,optical sensors may be used to measure blood perfusion in the tissue asa way of monitoring tissue flap viability. Other sensors such asultrasonic, thermal, or mechanical sensors could also be incorporatedinto the tissue holder plate 316 to provide additional channels ofinformation to support the surgical procedure.

Thus, the above described system and method allows for tissue flapdissection of substantially uniform thickness in non-anatomic planes.The systems and methods further allow for precise gaging of tissue flapdissection, thereby reducing the surgeon's margin of error and patientmorbidity.

The present invention has been described in terms of one or morepreferred embodiments, and it should be appreciated that manyequivalents, alternatives, variations, and modifications, aside fromthose expressly stated, are possible and within the scope of theinvention.

The invention claimed is:
 1. A surgical device for preparing a tissueflap from a tissue mass, the surgical device comprising: a guide plateincluding at least one of a peripheral ridge and a slot; a tissue holderplate configured to securely hold the tissue mass a predetermineddistance from and orientation to the guide plate; a support membercoupled between the guide plate and the tissue holder plate; and a toolholder configured to receive a cutting tool for cutting the tissue flapfrom the tissue mass, the tool holder comprising: a base; a tool holderplate coupled to the base, the tool holder plate dimensioned to engagethe guide plate and translate and rotate within the at least oneperipheral ridge and slot to restrict movement of the cutting tool to apredefined plane relative to the tissue mass and the tissue holderplate; a guide arm coupled to the base of the tool holder at apredetermined angle relative to the tool holder plate and configured toengage the cutting tool; and wherein movement of the tool holder platewithin the at least one peripheral ridge and slot of the guide plateenables the cutting tool to cut the tissue mass in the predefined planeat the predetermined angle, thereby preparing a tissue flap with asubstantially uniform predetermined thickness from the tissue mass. 2.The surgical device as recited in claim 1, wherein the cutting tool isat least one of a scalpel, an electrosurgical tool, a pencil, a scissorsand a Bovie knife.
 3. The surgical device as recited in claim 1, whereinthe tissue holder plate includes a perforated plate and a the vacuumchamber, thereby providing suction to hold the tissue mass in place. 4.The surgical device as recited in claim 3, wherein the perforated plateincludes a plurality of suction cups coupled to perforations defined bythe perforated plate, the plurality of suction cups configured to securethe tissue mass to the tissue holder plate.
 5. The surgical device asrecited in claim 3, further comprising at least one of a gel, glue, anda double-sided adhesive patch applied to at least one of the tissue massand the tissue holder plate to secure the tissue mass to the tissueholder plate.
 6. The surgical device as recited in claim 3, furthercomprising a valve system coupled to a vacuum hose attachment to controlthe suction provided by the vacuum chamber.
 7. The surgical device asrecited in claim 1, wherein the base of the tool holder includes a cordslot configured to receive a cord for powering the cutting tool.
 8. Thesurgical device as recited in claim 1, wherein the base of the toolholder includes an aperture configured to receive a base of the cuttingtool.
 9. The surgical device as recited in claim 1, wherein at least oneof the guide plate, the tissue holder plate, the base, the tool holderplate, and the guide arm are interchangeable with sized replacementsmatched to at least one of a patient size, a tissue flap size, and asurgical procedure.
 10. The surgical device as recited in claim 1,further including a cutting plane defined by the dimensions of the guideplate and the tool holder plate, wherein the dimensions of the guideplate and the tool holder plate determine the relative size of thepredefined plane.
 11. The surgical device as recited in claim 1, whereinthe tissue flap is prepared for at least one of a mastectomy, areconstructive surgery, a thin flap evaluation in mastectomy, and ageneral flap elevation.
 12. The surgical device as recited in claim 1,wherein the support member is an ergonomic handle adapted for aplurality of tissue flap sizes manipulated by the surgical device. 13.The surgical device as recited in claim 1, wherein the predeterminedangle of the guide arm determines the substantially uniform thickness ofthe tissue flap in the predefined plane.
 14. The surgical device asrecited in claim 1, further including a linkage configured to attach theguide plate and the tool holder plate, thereby enabling movement of thetool holder plate relative to the guide plate in the predefined plane.15. The surgical device as recited in claim 14, wherein the linkageincludes a magnet embedded within the tool holder plate configured tomagnetically attract the guide plate.
 16. The surgical device as recitedin claim 1, wherein the guide plate and the tool holder plate include aplanar surface.
 17. The surgical device as recited in claim 1, whereinthe guide arm is at least one of a cylindrical cut out, a clamp, and amechanical attachment.
 18. The surgical device as recited in claim 1,further including a sliding linkage coupled to the base of the toolholder and the guide arm, thereby forming an adjustable system to selectthe substantially uniform thickness of the tissue flap by verticallysliding the sliding linkage.
 19. The surgical device as recited in claim1, wherein at least one of the tool holder plate, the tissue holderplate, and the guide plate has a partial cylinder shape, therebyenabling the predefined plane to be non-linear.